Locking device.



J. 0. GARGAN.

LOCKING DEVICE.

APPLICATION mm MAYI3, 1918.

1,281,338. Patented Oct. 15,1918.

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UNITED STATES PATENT OFFICE.

JOHN O. GARG-AN, OI BROOKLYN, NEW YORK, ASSIGNOR T WESTERN EIl'JECTRIC COM- rm, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

LOCKING nnvrcn.

Specification of Letters Patent.

Patented Oct. 15, 1918.

a To all whom it may concern:

Be it known that 1, JOHN O. GABGAN, a' citizen of the United States, residing at Brookl n, in the county of Kings, State of New ork, have invented certaln new and. useful Improvements in Looking Devices, of which the following is a full, clear, concise, and exact description.

This invention relates to locking devices and more particularly to a locking device suitable for use in connection with adjustable condensers for the urpose of locking the movableplates of t e condenser in a fixed position.

In various types of apparatus there is a demand for a locking device which will hold the apparatus in a fixed adjustment without putting any strain on the various parts. Especially 1s thistrue in the case of variable air condensers used on aeroplanes for wireless communication or in other places where the apparatus is subjected to severe jars or vibrations. The movable plates of such a condenser are not balanced with respect to the rotatin shaft and a tendency therefore exists for t em to work out of position when subjectedto vibration. Also during shipment it is desirable to have these plates locked in position to prevent the apparatus from damage due to rough handling. Since there is only a slight separation between the movable platesand the fixed plates it is highlydesirable that the locking device employed be so constructed as to prevent any possibility of strains sufficient to change the separationbetween the two sets of plates.

t is, therefore, the object of the present invention to provide a locking device which may be used to look a moving member in position without causing any strain on that member and moreover, one which will be simple in operation and cheap to manufacture. To accomplish this object, a feature of the invention resides in providing a locln'ng device in which a pair of floating jaws are ar- I ranged to grip a movable member and hold it in a fixed position.

This and other features of the invention may be more clearly understood byreferring to the accompanying drawing in which Figure 1 is a plan view of a variable condenser fitted with the locking device embodying this invention; Fig. 2 is a side view of the condenser shown in Fig. 1; and Fig. .3 is a plates 99 are mounted on the shaft 10 c.

which is also provided with spacers 1111. The unsupported ends of the movable plates are prevented from being displaced by means of-spacers 1212 held in place by the screw 13 and the nut 14. ported at the upper end by the bearing 15 secured to an insulating member located within the invertedcup portion 16 of frame 5 and at the lower end by the bearing 17 located in a plate 1.8 of micarta or similar insulating material. This plate not only serves as a retainer for the lower bearing but also serves to add rigidity to the fixed plates. 7 The upper portion of shaft 10 extends through an opening in the mounting plate 19 to which the frame 5 is fastened and is provided with a knob or handle 20 secured to the shaft by the screw 21 and prevented from turning by a slot which engages the pin 22. A collar'23 and spring washer 24 are provided to prevent end play of shaft 10. Rigidly secured to the underside of handle 20 is an indicating plate 25 having a scale graduated thereon to indicate the position of the movable lates.

The locking device em odying the present invention is arranged to hold the movable plates in a 'fixed position by clamping against the indicating plate 25. This looking device consists of a .hollow post 26 rigidly secured to the mounting plate 19 and provided with ,a. longitudinal slot through which extends a air of floating jaws 27 and 28. The jaw 27 is assembled to lie in a plane below that of the indicating plate 25 and its inner end is provided with a threaded opening adapted to engage corresponding threads in the knurled head screw 29. The inner end of jaw 28 is provided with an opening through which the threaded portion of screw 29 passes freely and its outer end is pointed to serve as a pointer for the indicating plate 25. Between the jaws 27 and 28 within the post 26 is located a washer 30 of The shaft 10 is sup.- 1

a thickness somewhat less than that of the plate 25. Since the jaws are prevented from turning upon rotation of the screw 29, by the edges of the slot in the post 26, the lower jaw is drawn upward until it bears against the plate 25. Upon further turning of the screw 29, the shoulder portion 31 of the screw engages jaw 28, thereby clamping the indicatin plate 25 firmly in position without causing any strain which would tend to change the separation between the movable plates and the fixed plates. The function of the washer 31 is to cause the jaws to lie in a position approaching parallelism when gripping the indicating plate, and equally good results may be obtained by employing a small helical spring in place of the washer.

What is claimed is:

1. The combination with a movable member to be locked in position, of a locking-device comprising a pair of floating aws, means for preventing the rotation of said jaws, and additional means for drawing said jaws against the movable member with equal pressure.

2. The combination with a movable member to be locked in position, of, a locking device comprising a pair of floating jaws, a slotted member in which said jaws are positioned, and means .for drawing said jaws against the movable member with ;,'equal pressure.

3.---The combination with a movable mem her to be locked in positiom'of a locking device comprising a hollow member havin a longitudinal slot therein, a pair of floating jaws extending through said slot, -and means for causingsaid jaws to bear against the movable member with equal pressure.

4. The combination with a movable member to be locked in position, of a locking device comprising a hollow member havin a longitudinal slot therein, a air of floating jaws extending through sa d slot and. located on either side of the movable member, means for raising the lower jaw to bear against the movable member, and means for pressing the upper jaw downward to bear against the movable member with equal pressure.

5. The combination with a movable member to be locked in position, of a locking device comprising a hollow member having a slot therein, a pair of floating jaws extending through SBJdSlOt and having their outer ends located on either side of the movable member, a screw adapted to enga e threads in the inner portioliof one of sai jaws and having: shouldered portion ada ted to engage t e inner portion of the ot er of said aws to cause said jaws to bear against the movable member with equal pressures.

In witness whereof, I-hereunto subscribe my name this 8th day of May, A. D. 1918.

JOHN o. GARGAn. 

